Concrete mixer



Jan. 19, 1943. HAL 2,308,901

CONCRETE MIXER Filed June 5, 1941 3,Sheets-Sheet 1- I .32 gmmiww/GeorgeKVz'all Louis amzke ier,

Jan. 19, 1943. G ALL ET AL 2,308,901

CONCRETE MIXER Filed June 5, 1941' 3 Sheets-Sheet 2 and i Louis 6'.llillcemeier,

Jan. 19, 1943.

G. K. VIALL ET AL CONCRETE MIXER I Filed June 5, 1941 3 Sheets-Sheet 3jam/Mom I aeorgeffin all, and

- L0 uia G'Hillremeier;

Patented Jan. 19, 1943 CONCRETE MIXER George K. Viall and Louis G.Hilkemeier, Milwaukee, Wis., assignors to Chain Belt Company, Milwaukee,Wis., a corporation of Wisconsin Application June 5, 1941, Serial No.396,768

9 Claims.

The invention relates to concrete mixers or agitators, more especiallythose of the rotary drum type having a charging opening in the drumthrough which at least the cement and aggregates are introduced formixing, and a duct or hopper associated with such opening for primarilyreceiving such materials, as from the chutes of storage bins at abatching plant, and conducting or feeding them to and through theopening. A typical example of such apparatus is to be found in the priorapplication of our co-worker, Charles F. Ball, filed December 6, 1939,Serial No. 307,784, now Patent No. 2,265,- 751, granted December 9,1941, and for purposes of the present disclosure the invention has beenillustrated and will be described in connection with such a mixer,although, as will be readily appreciated by those skilled in the art, itis not necessarily limited to such a construction.

The mixer or agitator f the said Ball application is of thetruck-mounted type, with the mixing drum mounted upon the truck chassisfor rotation about a longitudinal axis which is inclined to thehorizontal. The lower end of the drum is closed, except that in mostinstances a water supply pipe passes axially through the lower head,while the higher end, which is or may be frusto-conical in form, is opento provide an ingress and egress passage for the raw materials and themixed concrete respectively. A shaft. is secured to the drum adjacentsuch opening and extends axially outward therefrom, and a charging ductor hopper structure is slidably but non-rotatably mounted on said shaftfor reciprocating movements toward and from the opening. The interior ofthe drum is provided with helical mixing blades of appropriate design toworm the material upwardly to and through the drum opening, ordownwardly away therefrom, dependent upon the direction in which thedrum is rotated, which direction may be controlled at will by theoperator. The normal position of the hopper structure is inward on theshaft with its lower end in co-operative relation to the drum opening tofeed the cement and/or aggregates to and through the opening. It alsooccupies this position while the materials are being mixed within thedrum,-during which time it serves to prevent discharge of such portionsof the partially or completely mixed materials as may rise or be workedup by the mixing blades to above the lowest point of the drum opening,since such portions merely enter into and circulate in the hopperstructure, and return to the drum by gravity action. When it is desiredto discharge the completed mixture the hopper structure is movedoutwardly on the shaft to space its lower end from the drum opening,whereupon as the mixture is wormed up to the opening by the helicalblades it Will fall between the drum end and hopper structure into adischarge chute or receptacle positioned below the opening and hopperstructure.

' The hopper structure is open at its top so that upon arrival at thebatching plant it is only necessary to spot the machine with the hopperin position beneath the discharge chutes of the supply bins, whereuponthe desired measured quantities of cement and aggregates may be quicklytransferred to the drum. The open top of the hopper however, will alsopermit the entrance into the drum of undesired materials or substanceseither before the truck reaches or after it leaves the supply bins. Forexample, the mixer may be caught in a sudden shower in transit or on thejob, during which rain water may enter the drum through the hopper insufficient quantities to materially change the watercement ratio in themix, with consequent ill effects upon the concrete.

It is the principal object of the present inven tion to providerelatively simple but effective mechanism for protecting the drums andhoppers against the entry of any such undesired substances or materials.

It is a further object of the invention to provide mechanism of thatcharacter which will in no way interfere with the normal functioning ofthe charging device.

It is a still further object of the invention to provide mechanism ofthe kind described which may be simply and quickly manipulated to permitthe introduction of the cement and aggregates into the hopper and drum,and will not interfere with the discharge of the mixture from the drum.It is a still further object of the invention to provide mechanism ofthe class described which will automatically accommodate itself, whilein its protective position, to the movements of the hopper structure toand from the position in which the mixture may be discharged from thedrum.

It is a still further object of the invention to provide protective orshielding mechanism for the charging hopper structures of concretemixers which may be remotely controlled; as for example, in the case ofa truck-mounted mixer having a charging hopper at its rear end, the

protective mechanism therefor may be manipulated from the truck cab oradjacent thereto.

It is a still further object of the invention to provide mechanism of thclass described which, while effectively accomplishing its intendedpurpose of excluding undesired materials or substances from the mixingdrum, will at the same time preserve free communication between theinterior of the drum and the outside atmosphere, whereby dangerousbuilding up of gaseous pressures resulting from the chemical reactionsbetween the cement and water of the mixture will be avoided.

With the above and other objects in view, which will appear as thedescription proceeds, the invention resides in the novel details ofconstruction, and in the novel combinations and arrangements of parts,more fully hereinafter described, and pointed out in the appendedclaims.

Referring to the accompanying drawings forming a part of thisspecification, in which like reference characters designate like partsin all the views:

Figure 1 is a side elevational View of the essential elements of atruck-mounted concrete mixer of the type set forth above, showing oneform of protective mechanism for the hopper, constructed and arranged inaccordance with the present invention, applied thereto;

Fig. 2 is an enlarged fragmentary plan view of theparts shown in Fig. 1;

Fig. 3 is a still further enlarged fragmentary elevational sideelevational view, partly broken away and in section, of the shield andits actuating mechanism;

Fig. 4 is an end elevational view, also partly broken away and insection, as seen from the right of Fig, 3;

Fig. 5 is a fragmentary side elevational View, partly in section, of thecontrol lever and linkage for the shield;

Fig. 6 is an end elevational view of the same, as seen from the left ofFig. 5;

Fig. '7 is a detail sectional elevational view of one form of means foraccommodating the shield to the movements of the hopper to and fromdischarge position, taken approximately on the plane indicated by theline of Fig. 4, looking in the direction of the arrows;

Fig. 8 is a fragmentary side elevational view of a somewhat modifiedform of the invention;

Fig. 9 is an end elevational view of the parts illustrated in Fig. 8, asseen from the right of the latter Figure;

Fig. 10 is an enlarged horizontal sectional plan view, takenapproximately on the plane indicated by the line Ill-40 of Fig. 8,looking down; and

Fig. 11 is a sectional elevational view, taken approximately on theplane indicated by the line Il-ll of Fig. 8, looking in the direction ofthe arrows.

Referring more particularly to Figs. 1 to '7 inclu'sive of the saiddrawings, the concrete mixer or agitator here shown comprises the mixingor agitating drum or receptacle l5 mounted upon the chassis E6 of amotor vehicle for rotation about a longitudinal axis I! which isinclined to the horizontal as in the said prior Ball application. Thedrum 15 may be rotated in either direction at the volition of theoperator through a suitable power transmission l8 deriving power eitherfrom the truck motor or from an independent motor in accordance withwell known practice. At the rear upward end of the drum, which as aboveindicated is open to provide a asoaeoi charging and discharging opening,the apparatus is provided with a hopper device slidably butnon-rotatably mounted upon a shaft, not shown, but carried by the drumand extending axially outwardly from the rear end of the drum. The saidhopper device is reciprocated upon the said shaft along the axis I? bysuitable connections including hand operated gearing 2|, being movablefrom a normal position in which its lower or discharge end is inproximity to the drum opening whereby to transfer the concrete materialsthrough the latter, to a discharge position in which the said lower endis spaced from the drum end so that the mixture, as it is moved upwardlyin the drum by the mixing blades, will be discharged from the opening,dropping between the drum end and the hopper device into the dischargechute 22. The said hopper 20 is perimetrally closed but is open at thetop, and as above indicated not only the desired concretemakingmaterials may enter through this open top but also undesired substancessuch as the rain water above mentioned.

The mechanism for preventing the entry of such undesired materialscomprises a plate of suitable shape and dimensions to overlie andprotect or shield the open top of the hopper, which plate has aresilient connection 2'6 with one end of a curved arm 21. As best shownin Figs. 4 and 7, the other end of said arm is journalled in a sleeve 28which is rigidly carried by a link 29 pivotally mounted as at 30 in ears3! carried by an upright hollow shaft or tube 32. This tube 32 isjournalled in bearings 33 and 34 carried by members 35 of the mixerframework and adjacent the lower bearing 34 it rigidly carries thebracket arms 35 by means of which it may be oscillated in the saidbearings as will appear more fully below.

The link 29 extends through slots 31 provided in the upper end of thetube 32 and has pivotally connected to it as at 38 an elevating shaft 39which extends downwardly within the tube 32. This shaft has pivotallyconnected to its lower end as at 46 an arm 4| which is rigidly carriedby the stub shaft 42 journalled in the free ends of the bracket arms 36,as will be clear from Figs. 3 and 4. The said stub shaft is connected bya universal joint 43 to an operating rod 44 which extends forwardly to apoint preferably adjacent the cab of the vehicle, as indicated inFig. 1. Here the said rod is pivotally connected as at 54 to theoperating lever 45 mounted in a slot 46 of a plate or bracket 41, whichslot has an offset 48 at its forward end into which the said lever maybe laterally moved to normally look the parts in the positions shown inFigs. 1 and 2.

The rod or shaft 44 is slidably and rotatably mounted in a bearingbracket 49 carried by the plate or bracket 41 and the lateral movementsof the operatinglever 45 to and from the offset 48 of the slot 46 willimpart oscillatory movements to the shaft 44 as indicated in Fig. 6. Thelower end of the lever 45 is pivotally connected asat iii] to a pair oflinks 51 which in turn are pivotally connected as at 52 to the downwardextension 53 of the bearing 49, the pivotal connections 59 and 52 beingsufficiently loose to permit of the lateral displacement of the lowerend of the said lever 45, as indicated in said Fig. 6. In addition tothe oscillatory movements thus imparted to the shaft 44, swingingmovements of the lever 45 in the slot 45 about the pivot will impartlongitudinal movement to the said shaft and inturn to the arms 35carried by the tube 32.

It results from the construction so far described that with the parts inthe positions illustrated in full lines in Figs. 1 to 4 inclusive, ifthe operating lever 45 be moved laterally to disengage it from theoifset 48, such lateral movement will impart arcuate movement to theshaft 44 which will be transmitted through the universal joint 33 to thestub shaft 42 and by the arm 4| carried thereby to the elevating shaft39, the upward movement of which will raise the link 29, sleeve 28, arm21 and the shield plate 25 about the pivot 38 to the broken lineposition illustrated in Fig. 4. Longitudinal movement of the operatinglever 45 in the slot 46 will then transmit longitudinal movement to thesaid shaft 44, which in turn will be transmitted through the universaljoint 43 to the arms which will cause arcuate movement of the tube 32 inits bearings 33 and 3d, thereby swinging the arm 2'! and plate 25 aboutthe vertical axis of the tube 32 to move the parts from the full lineposition shown in Fig. 2 to the broken line position indicated therein,thereby moving the shield plate 25 to an ineifective position so far asthe hopper 2G is concerned to permit the introduction into the hopperand from it to the mixing drum of the cement and aggregates from thesupply bins or other source of supply. After the materials have beencharged into the hopper and drum the lever 55 is returned to its initialposition during which movements the shield and its actuating memberswill be returned to their respective initial positions by movements inthe reverse order from that above described.

As above indicated the hopper 29 is movable by the mechanism 2| axiallyaway from the charging opening for discharge purposes. Since suchmovements are rearwardly and upwardly due to the inclination of the drumaxis and the rum-carried shaft upon which the hopper is mounted, it ispreferred to provide resilient or other yielding means in the shieldmounting whereby to accommodate the shield to such hopper movements. Themean-s here shown for this purpose are incorporated into the sleeveconnec tion 28 for the curved arm 2! and comprise the pin 55 carried byand extending through the arm 2'5 and Working in slots 56 provided inthe wall of the sleeve 28, see Figs. 4 and 7. One end of a coil spring59 is secured to the said pin 55 While the other end of the said springis secured to a pin or stud 50 which is rigidly carried by the sleeve28. It thus results that as the hopper 20 moves upwardly and rearwardlythe upward component of such motion will elevate the plate 25, the arm21. journalling in the sleeve 28 and through the pin 55 tensioning thespring 59, which latter will of course retain the plate in engagementwith the hopper and cause it to maintain such engagement as .the hopperis again lowered. During the outward and upward hopper movement theoutward component will be taken care of by the hopper merely slidingsomewhat from beneath the shield as indicated in broken lines in Fig. 3.

As was above mentioned, it is desirable to have the shield maintain opencommunication between th interior of the drum and hopper and the outeratmosphere in order to prevent the building up of dangerous pressureswithin the drum due to gases generated as a result of the chemicalreactions between the water and the cement.

To this end the hopper is preferably provided with a plurality ofspacing members 62 extending a slight distance above the upper edge ofthe hopper and which are contacted by the plate 25 in its normalposition, as clearly shown in Figs. 1, 3 and 4. These members 62 ofcourse keep the plate 25 spaced sulficiently from the hopper to permitof the escape of any gases which may be generated within the drum, andalso to promote the free circulation of air within the drum from theouter atmosphere, but the spacing is not great enough to allow undesiredsubstances in appreciable quantities to enter into the hopper.

In the somewhat modified form of the invention illustrated in Figs. 8,9, 10 and 11, the arm 21 which carries the shield 25 is journalled inthe upper curved end of the tubular shaft 65, there being a resilientconnection, such as that shown in Fig. 7 and above described, providedbetween the arm and tube as shown in Fig. 9. The tubular shaft 65 isvertically mounted in bearings 66 and 57 carried by the frame members ofthe mixer unit for both oscillatory and axial movements which aresequentially imparted thereto by the elements shown at the lower portions of Figs. 8 and 9 and somewhat more in detail in Figs. 10 and 11.

These elements comprise an arm ill journalled on the lower end of thevertical shaft 55 but held against longitudinal movement thereon. Thearm is provided with a downwardly extending lug or projection H whichengages the upper surface of the bearing bracket El. This bracket isprovided with an inclined camming portion 12 over which the saidprojection may travel, as best shown in Fig. 11, as the arm it isoscillated by means of the reciprocating rod or shaft 13 which extendsforwardly in the same manner as the rod 44 above described, and isoperable by a hand lever 14 moving in a slot 15 formed in the plate orbracket 16 mounted adjacent the forward end of the mixer unit. Thislever 1'4 is also laterally movable in much the same manner as the lever45 above described into and out of an offset 1'! with which the slot 75is provided. However in this instance the lateral movements of the saidlever are utilized solely for locking purposes and are not translatedinto oscillatory movements of the connecting rod 73, since the elevationof the shield 25 preparatory to its being swung from over the hopper isaccomplished through the camming action of the lug or projection Hriding up the camming surface E2 of the bracket 51. This camming actionof course raises the arm 70 which, being held against axial movement onthe vertically extending shaft 65, elevates the latter bodily and withit the arm 21 and plate 25.

The shaft 65 is provided with a rigid arm 85) mounted just above the armH1 and having an adjustable stop screw 8! which is engageable with a lugor projection 82 rigidly carried by the upper surface of the arm It. Theparts are so constructed and arranged that the lug 82 will not engagewith the stop screw 81 until the elevating lug H has moved to the brokenline position indicated in Fig. 10 and substantially completed itselevating function due to its movement over the inclined camming surface12; but when this action has been completed engagement of the lug 82with the stop screw 8! will then transmit any further arcuate movementof the arm 10 to the arm and through it to the shaft 65, therebyswinging th arm 21 and shield 25 to the inoperative position similar tothat indicated in broken lines in Fig. 2, and uncovering the hopper forthe admission of concrete constituents. A spring 85 may be attached tothe arm 80 and to some fixed element, as for example one of the framemembers, to return the shield 25, arm 21 and vertical shaft 65 to thenormal or operative position of the parts, as will be readily understoodfrom Figs. 8, l0 and 11. A cushioning spring 8'! may be interposedbetween the bearing bracket 66 and a collar 88 carried by the tubularshaft 65, to reduce noise in transit.

The shield illustrated in Figs. 8 and 9 is shown as slightly dished toassist it in shedding rain water, and the said shield is preferablyspaced from the upper edge of the hopper by spacing members 62 as in thepreceding form.

While two forms of the invention have been illustrated and described itis obvious that those skilled in the art may vary the details ofconstruction as well as the precise arrangement of parts withoutdeparting from the spirit of the invention and therefore it is notwished to be limited to the above disclosure except as may be requiredby the claims.

What is claimed is:

1. In a concrete mixer or agitator having an agitation receptacleprovided with an opening for the charging of the concrete materialsthereto and the discharge of the mixture therefrom, and an open hopperdevice for receiving and transferring the materials to and through saidopening, said hopper device being movable away from the opening for thedischarge of the mixture, a shield for said hopper device, normallypositioned to exclude materials from the hopper opening; means mountingsaid shield separately from the hopper while accommodating the movementsof the hopper to and from discharge position; and means for moving theshield to an ineffective position relative to the hopper opening when itis desired to admit materials .to the hopper.

2. In a concrete mixer or agitator having an agitation receptacleprovided with an opening for the charging of the concrete materialsthereto and the discharge of the mixture therefrom, and an open hopperdevice for receiving and transferring the materials to and through saidopening, said hopper device being movable away from the opening for thedischarge of the mixture, a shield for said hopper device, normallypositioned to prevent entry of materials into the hopper; means mountingsaid shield separately from the hopper said means being yieldable toaccommodate the movements of the latter to and from discharge position;and means for moving the shield to an ineffective position relative tothe hopper when it is desired to admit materials to the latter.

3. In a concrete mixer or agitator having an agitation receptacleprovided with an opening for the charging of the concrete materialsthereto and the discharge of the mixture therefrom, and an open hopperdevice for receiving and charging the materials to and through saidopening, said hopper device being upwardly movable away from the openingfor the discharge of the mixture, a shield for said hopper device,normally positioned to prevent entry of materials into the hopper; amounting for said shield, supporting it independently of the hopper andincluding means resiliently urging it into engagement with the hopper toaccommodate the upward movements of the latter to its dischargeposition; and means for moving the shield to an ineffective positionrelative to the hopper when it is desired to admit materials to thelatter.

4. In a concrete mixer or agitator unit having an agitation receptacleprovided with an opening for the charging of the concrete materialsthereto and the discharge of the mixture therefrom, and an open hopperdevice for receiving and charging the materials to and through saidopening, said hopper device being movable outwardly and upwardly awayfrom the opening for the discharge of the mixture, a shield for saidhopper device, normally positioned to prevent admission of materialsinto the hopper; means mounting said shield eparately from the hopperwhile normally maintaining it in engagement with the hopper, saidmounting means being yieldable to accommodate the upward component ofthe hopper movement, and the hopper sliding beneath the shield toaccommodate the outward component of said movement; and means for movingthe shield to an inefiective position relative to the hopper when it isdesired to admit materials thereto.

5. In a concrete mixer or agitator unit having an agitation receptacleprovided with an opening for the charging of the concrete materialsthereto and the discharge of the mixture therefrom, and an open hopperdevice for receiving and charging the materials to and through saidopening, said hopper device being rectilinearly movable away from theopening on an axis inclined to the horizontal for the discharge of themixture, a shield for the hopper opening; a resilient mounting for saidshield supporting it independently of the hopper and normallymaintaining it in engagement with the hopper to prevent entry ofmaterials thereto while yieldably accommodating the upward component ofsaid hopper movement, the outward component of which is accommodated bysliding of the hopper relative to the shield; and means for moving theshield to an ineffective position relative to the hopper when it isdesired to admit materials thereto.

6. In a concrete mixer or agitator unit having a frame, an agitationreceptacle provided with a material transfer opening mounted in saidframe, and an open hopper device for receiving and charging at least thesolid constituents for the mixture into the receptacle through saidopening, said hopper device being upwardly movable away from the openingfor discharge of the mixture; means for excluding undesired mate rialsfrom said hopper and receptacle, comprising a shaft journaled on theframe adjacent the hopper for movements about a vertical axis; an armextending substantially horizontally from said shaft toward the hopperand journaled for movements about an approximately horizontal axis; ashield carried by said arm for controlling the entry of materialsthrough the open top of said hopper; means yieldably biasing said armabout said horizontal axis to maintain said shield in operative positionrelative to the hopper while accommodating said upward movement of thelatter for discharge; and means for sequentially bodily elevating saidarm and shield from the hopper, and then swinging said shaft, arm andshield about said vertical axis, to remove the shield from the hopperfor charging.

'7. In a concrete mixer or agitator unit having an agitation receptacleprovided with a charging opening, and a charging hopper for receivingand transferring concrete materials to said opening, means for excludingundesired materials from said hopper comprising a vertical shaft mountedadjacent and separately from the hopper; a shield for the hopper carriedby said shaft for vertical and horizontal movements to and from aposition in which it may prevent entry of materials to the hopper; meansother than the shaft for imparting said vertical movements to theshield; an operating lever; and connections between the lever, shaft andvertical moving means whereby actuation of the lever will cause saidmeans to elevate and lower the shield and said shaft to imparthorizontal movements thereto.

8. In a concrete mixer or agitator unit having an agitation receptacleprovided with a charging opening, and a' charging hopper disposed incooperative relation to said opening for receiving and conductingconcrete materials thereto, means for excluding undesired materials fromsaid hopper comprising a vertical shaft mounted adjacent andindependently of the hopper for rotative and axial movements; a shieldcarried by said shaft for vertical and horizontal movements to and froma position relative to the hopper in which it may prevent entry ofmaterials to the hopper; an operating lever; and connections betweensaid lever and shaft including cam means for imparting initial axialmoveinents to the latter, whereby the shield may be moved from itseflective position.

9. In a truck-mounted concrete mixer or agitator of the type wherein amixing or agitating unit is mounted adjacent the truck cab and comprisesa frame, an agitation receptacle provided with a charging opening at adistance from the cab, and an open charging hopper disposed inco-operative relation to said opening for receiving and transferringconcrete materials thereto, means for excluding undesired materials fromsaid hopper, comprising a shield mounted on said frame for movements toand from a position over the hopper in which it may prevent theadmission of materials thereto; an operating lever mounted adjacent thetruck cab; and connections between said lever and shield for moving thelatter to and from its said position.

GEORGE K. VIALL. LOUIS G. HILKEMEIER.

